Deep multiple sclerosis lesion phenotyping using multimodal quantitative MRI

Quantitative MRI has the potential to disentangle the heterogeneity of multiple sclerosis (MS) lesions in vivo, which can be decisive for treatment and monitoring. In this study, we distinguished different types of MS lesions based on quantitative susceptibility mapping (QSM) and characterized them using T1 relaxometry, diffusion imaging and myelin mapping. We identified four types of lesions (hypo/isointense, homogeneous hyperintense, inhomogeneous hyperintense and paramagnetic rim), which were characterized by increasing degrees of axonal and myelin disruption. Paramagnetic rim lesions were closer to the ventricular CSF, corroborating the presence of a noxious activity of CSF in MS pathology.